The present disclosure relates to fluid machinery, and more particularly to high pressure casings for such machinery.
Fluid machinery such as centrifugal compressors each typically includes a casing for containing working components such as one or more impellers mounted on a rotatable shaft. The casing includes one or more inlets for directing fluid inwardly toward the compressor working components and one or more outlets for directing pressurized fluid outwardly from the casing for subsequent processing or ultimate usage. Further, such compressor casings often include one or more openings to provide access to maintain or repair components of the compressor, for example, shaft bearings, etc. Such access openings must be closed by a hatch or cover during normal compressor use.
Since a variety of compressors are operated at relatively high pressure, the access covers are required to resist this high pressure, and are therefore often relatively thick, require the machining of a protrusion for mounting the cover, and are typically secured by a relatively large number of fasteners or bolts. Since these compressors may operate in hostile environments such as sub-sea applications, the cover bolts could be subject to deterioration, which may lead to failure of the entire compressor.